Prestashop update

Closed - This job posting has been filled and work has been completed.

Job Description

We have two websites built on Prestashop. They are both office supplies web stores with almost 15k items. We are not satisfied with the completed job and the company who built it is reluctant to do any more work on it.
We need to the search engine to work more efficiently, ensure all items are in the database, set up separate price lists for users plus some other cosmetic items on the site.
We need some who is very experienced with Prestashop and a database of this size.
What information from the site will you need to do the work and how long do you think this will take to complete.